I would like to migrate this legacy Java example code to Java 8.
public String getUserSex(Person person) {
if(person != null) {
if(person.getSex() != null) {
return person.getSex();
}
}
return null;
}
How to migrate this to Java 8 using Optional?
Use Optional.ofNullable and Optional.flatMap
public Optional<String> getUserSex(Person person)
{
return Optional.ofNullable(person).flatMap(
p -> Optional.ofNullable(p.getSex())
);
}
You could implement it as follows:
public Optional<String> getUserSex(Person person) {
if(person != null) {
return Optional.ofNullable(person.getSex());
}
return Option.empty();
}
In that case the caller of getUserSex will always get an typed Optional an therefore the caller must not implement null checks.
Instead the caller can ask the Optional if the value is present.
getUserSex(new Person()).isPresent()
